This dissertation examines factors (verb bias and plausibility) that influence reanalysis processes in native and non-native processing of English and Mandarin garden-path sentences (Chapters 2 and 3) and the relationship between the amount of reanalysis and final interpretation of such sentences (Chapter 4).
Verb bias refers to the likelihood of a particular verb taking a particular argument structure, such as a direct object (DO) or a sentential complement (SC). Previous research has demonstrated that native speakers of English are able to use verb bias information fast enough to generate predictions about the upcoming syntactic structure and that verb bias plays a larger role than plausibility in this predictive process (e.g., Garnsey, Pearlmutter, Myers, & Lotocky, 1997). However, little is known about the relative importance of verb bias and plausibility in second language sentence processing. A prevailing view in the L2 psycholinguistic literature claims that L2 learners underuse structural cues during real time processing, and that to compensate, they rely predominantly on lexical-semantic cues (Clashen & Felser, 2006). What has not been considered on this view is the use of lexically-associated structural cues, such as verb bias. Since such information is both lexical and structural, it is unclear whether L2 learners would be able to use these cues in real-time processing. In two self-paced reading experiments, Chapter 2 compared L1-Mandarin speakers of L2 English and L1-Korean speakers of L2 English with native English speakers on the resolution of temporary DO/SC ambiguity in sentences. Results showed that similar to native speakers, both L2 groups were able to use verb bias cue to predict the likely type of following structure, but were unable to use the plausibility cue predictively when the verb bias cue was present, challenging the view that L2 learners rely more on plausibility than syntax during parsing.
While substantial research has been conducted on verb bias effect in English, few studies have examined such effects in other languages, especially in languages that have been found to rely more on plausibility than structural information, such as Mandarin (Su, 2001a, 2001b, 2004). In one self-paced reading experiment, Chapter 3 compared the relative contributions of verb bias and plausibility in processing Mandarin sentences that bore the surface level resemblance to English sentences with temporary DO/SC ambiguity. Since Mandarin allows null subjects, such a structure is temporarily ambiguous between an embedded clause and a blended structure, in which the object of the first clause is also the subject of the second clause. Results showed that verb bias trumped plausibility in Mandarin, such that readers made use of verb bias cues to anticipate the following structure and were only sensitive to plausibility information when verb bias allowed it, contrary to the claim that Mandarin relies heavily on plausibility in sentence comprehension.
In Chapters 2 and 3, reading time (RT) at the disambiguating region in sentences was used as the diagnostic in determining the effects of verb bias and plausibility, based on the assumption that RT at the disambiguation reflects the amount of reanalysis work. In two self-paced reading and two event-related brain potential (ERP) experiments, Chapter 4 demonstrated that RT and ERP on-line measures at the disambiguation might not reflect primarily reanalysis, since both RTs and the amplitudes of the P600 and N400 ERP components were found to be unrelated to the accuracy of the final interpretation of garden-path sentences, as measured by responses to post-sentence questions, thus calling into question traditional assumptions about the meaning of traditional measures. The original prediction was that more time/effort spent reanalyzing at the disambiguation would lead to more success in question responses. Instead, whenever there was any trend toward a relationship between the online measures and question responses, it was opposite the predicted direction, i.e., when more time/effort was spent on the disambiguation, questions tended to be answered less accurately. Chapter 4 thus proposed that the RTs and ERP component amplitudes at the disambiguation may reflect the amount of confusion about and/or competition between different possible interpretations, rather than or in addition to any reanalysis triggered there. Overall, this dissertation examined the reanalysis processes at the disambiguation in garden-path sentences in both native and non-native sentence processing and the link between the reanalysis processes and the final interpretation in native sentence processing. It paved the way for conducting similar research on the final interpretation of garden-path sentences by L2 learners.